- Created: Wednesday, 02 February 2011 14:10
- Published: Wednesday, 02 February 2011 14:10
By Carol WassonCHALLENGE:
To ramp up production of crushed stone to serve a major natural gas exploration project.
Three Telsmith portable crushing plants.
The hydraulic adjustment technology on the jaw allows the company to change from one material to another in a matter of minutes.
The Marcellus Shale formation is the nation’s largest recoverable natural gas reservoir. Largely located in Pennsylvania, this super-giant field was identified by the United States Geological Survey (USGS) some years ago, but has only recently been tapped by new horizontal drilling technologies and hydraulic fracturing methods which extract the natural gas from the thick black rock some 6,000 ft. underground. In early 2008, experts estimated that the Marcellus might contain more than 500 trillion cu. ft. of natural gas – a stunning prediction that left area entrepreneurs with no time to waste.
One such company is Powers Stone Inc., whicho is currently providing crushed stone for natural gas drilling pads, as well as for access-road construction projects. Following in the footsteps of a prior generation, brothers Mark and Ron Powers are at the helm of this Montrose, Pa.-based operation, which has long been at the center of the region’s dimensional bluestone and flagstone market.
The latter is an industry that requires a well-honed specialization to blast, remove and precision-cut the large, valuable stone blocks for decorative use – a process that creates a certain amount of “so-called” waste stone that is stockpiled over time. The Powers brothers had a small track plant to crush the “waste” material as needed for sale into typical aggregate markets. But when the gas boom hit, so did the demand for crushed stone – and as the old saying goes, “Waste not. Want not.” It was time for Powers Stone to take on the crushed stone market in much bigger way – with higher capacity equipment and additional crushing locations – and they needed to do it very quickly.
After researching a number of plants, Powers Stone chose three Telsmith portable plants; the first being a primary jaw plant which includes a 3258 hydraulic jaw crusher – a model that tops conventional crusher capacity due to a 32-in. gape and a 58-in.-wide crushing chamber. The plant also features a 60-in. by 20-ft. vibrating grizzly feeder, and a 54-in.-wide conveyor. For optimum portability, the grizzly feeder, loading hopper and grizzly bypass chute comprise one modular unit.
The second portable plant is a Telsmith 6-ft. by 20-ft., triple-deck, horizontal screen; and the third, a Telsmith Model 52SBS cone plant. Each plant is on its own chassis which will allow the operation more flexibility over the long term, as new crushing locations come into play.
“Telsmith was able to respond very rapidly to our needs. It was just a matter of a couple of weeks before we took delivery and were up and running with our primary components,” said Powers Stone Co-Owner Mark Powers. “But even though availability was of major importance, we also needed equipment that would maximize capacities and plant uptime,” he said, adding that he got those benefits with production numbers averaging up to 750 tph depending upon the material feed and the product being processed.
As to plant uptime, Powers specifically points to the innovative hydraulic systems on the Telsmith 3258 jaw plant. “The hydraulic adjustment technology on the jaw allows us to change from one material to another in a matter of minutes rather than the two hours required when using older jaw models. Quite simply, it’s the turn of a switch instead of a turn of a wrench,” he said.
According to Telsmith engineers, the Model 3258 jaw incorporates hydraulic tensioning cylinders that replace conventional toggle tension rods and springs. As a result, the tension cylinders automatically maintain the proper tension on the toggle, eliminating the need for spring adjustment. With proper tensioning being automatic, producers save time as well as reduce wear and tear on parts.
Furthermore, two oversized hydraulic cylinders behind a moving toggle beam enable all closed side setting (CSS) adjustments. A flip of a switch extends or retracts the cylinders and the adjustment is complete – and made safely without shims being needed at any time.
For safe toggle maintenance, the hydraulic adjustment cylinders push the pitman forward where it is locked into position with lock-out pins which insert from the side. Then hydraulic tension cylinders, mounted on the side of the toggle, pull the toggle beam back, allowing it to be safely lowered away. Powers stresses that this safety aspect is very important to them. “We don’t need to have workers with wrenches climbing in, around or under this equipment,” he said.
As to following the portable jaw plant with the Telsmith 52SBS portable cone plant, Powers said that the jaw/cone combination makes the most sense in efficiently achieving their cost-per-ton targets, while also being the most suitable matchup for their somewhat abrasive material. He likes the hydraulic systems in the 52SBS as well, particularly the Dynamic Adjust system which maximizes uptime by enabling adjustment under load. Also, the hydraulic anti-spin system is critical in extending the liner life of the cone.
When the crushing circuit stops, elongated pieces are minimized as the machine is not spinning, but is already oscillating in the crushing mode. Without an anti-spin, the cone will spin quite rapidly, with a lot of rock passing through the crusher in order to slow it down and make it go into the crushing mode.
A Welcome Expansion
Finding the right equipment at the right time has been integral to Powers Stone’s ability to serve the expansive natural gas market, especially when one considers that just one well-drilling pad may require more than 8,000 tons of crushed stone. “After just entering this market a year ago, we are experiencing a welcome expansion to our business with two larger quarry operations coming online in the near future,” said Powers.
Before 2000, many natural gas wells had been completed in the Marcellus; however the yields of these wells were often unimpressive. For new wells drilled with the new horizontal drilling and hydraulic fracturing technologies, initial production is far higher, with some wells exceeding one million cu. ft. of natural gas per day.
This presence of recoverable gas relative to the high population areas of New Jersey, New York and New England is of great significance and gives the Marcellus gas region a distinct advantage. If production reaches predicted estimates, the economic boost to the region could be sustained for several decades. E
According to the Marcellus Shale Coalition, the development of natural gas from Marcellus Shale offers great potential for the region’s economic future, as well as the thousands of individuals, families and small, locally-owned businesses involved in extracting this clean-burning and abundant energy source from the ground.
Pennsylvania currently imports almost 75 percent of the natural gas it uses every day. The Marcellus Shale formation holds enough recoverable natural gas reserves to not only serve Pennsylvania’s needs, but to turn the Commonwealth into a significant exporter of energy, generating equally significant economic benefits.
The production of natural gas from the Marcellus Shale formation is important because it produces a clean-burning, Pennsylvania-based energy source in an environmentally sound manner. It also provides economic benefits to communities across the Commonwealth.
Natural gas producers already invested more than $4 billion in Pennsylvania in lease and land acquisition, new well drilling, infrastructure development and community partnerships, with an even greater investment expected in the future.